Alternative Definitions of Cerebral Aneurysm Morphologic Parameters Have an Impact on Rupture Risk Determination

BACKGROUND: A discrepancy between definitions of morphologic parameters describing cerebral aneurysms across studies leads to conflicting results concerning performances of these factors and threshold values for rupture status prediction. The aim of the study was to evaluate how various definitions of morphologic parameters may influence the prediction of the risk for aneurysm rupture. METHODS: A total of 425 intracranial aneurysms were reviewed. Analyzed factors included demographic and clinical parameters, aneurysm maximal height (Hmax), dome length (Dlength), dome width (Dwidth), dome maximal diameter (Dmax) and dome minimal diameter (Dmin), neck length (Nlength), neck width (Nwidth), and neck maximal diameter (Nmax) and neck minimal diameter (Nmin). Alternative definitions of aspect ratio (AR), bottleneck factor (BNF), and height-to-width ratio (HW) were used. Univariate and multivariate analysis were performed to identify predictors for aneurysm rupture. RESULTS: Hmax, AR defined as Hmax/Nwidth and Hmax/Nmin, BNF definitions using Nwidth and Nmin, and selected definitions of HW (Hmax/Dlength and Hmax/Dmin) were indicated as potential predictors for rupture. Aneurysm location was found to be a confounding factor with statistical significance. AR defined as Hmax/Nwidth and Hmax/Nmin were the best performers (P < 0.001; area under the curve, 0.64). In multivariate analysis, AR defined as Hmax/Nwidth and aneurysm location with significantly higher risk for rupture of anterior communicating artery aneurysms were independent predictors for subarachnoid hemorrhage. CONCLUSIONS: Different definitions of aneurysm parameters affect various rupture risk determination. AR defined as Hmax/Nwidth and aneurysm location with significantly higher rupture risk of anterior communicating artery aneurysms are independent predictors for aneurysm rupture.